Power-driven scaffold



. R. N. RIBLET '7 POWER DRIVENSCAFFOLD March 5, 1946. 2,396,127

Filed Sept. 11', 1944 2 Sheets-Sheet l X I. I I

Iniventor (Ittotneg Patented Mar. 5, 1946 UNITED STATES A -Eur OFFICEPOWER-DRIVEN 'SCAFFOLD g 7 Royal Newton RibletQSpokane, Wash." japplication September 11, 1944, Serial No. 553,593

"This invention relates-toapower driven scar. fold and, moreparticularly to a scafiold elevator mechanism which may be rapidly andsmoothly raised or lowered in use on the face of buildings, tanks or thelike or which may be suspended relative to frame structures or bridgesor hangers for cleaning or painting operations. j

It is an object of this invention to provide, in

power-driven suspended type elevator] cage, suspending chains "overwhich, .in, a double reverse bend thereof, the cage may be movedsmoothly withoutrpossibilitytof slippage'or the application tndu we httotheca i Another obiectof this invention isthe provision'irieangelevatorjcage as pdescribed, of a" M I H i p v Theforegoingobj'ects and others ancillary thereto I prefer to accomplish'as follows:

According toa preferred embodiment of my invention, Iprovidean elevatorcage having a working platformiincorporated therein. Above theplatformin thecage structurel'mount a chain guide nieans,-either"'singlyor in a'pair and the preferred form at "this time takes the shape of atube extendingifro m above the platform to a point therebelow.:Belowthe, platform is mounted arpair' of chain pulleys one above th'oth'er and one of these pulleys is connected operatively with meanssuch as a; motor whereby the same is rotated "Such amotor is'us'ually ofthe-reversible type and control above-the-platform permits the user toselectively rotate'th'e motor, and hence, the connected pulleyr'asdesired. A chain is suitably suspended overhead and passes through thecl'iainguid below and "around, a portion of thelower pulley'thenc'e upto and around and over the-upper Tpulley; from whence the free enddepends; .:I have found it advisable from a safety standpointtoniploytwo such chairguides, chain and pull'ey assemblies both forstabilizing the cage and to insure smooth and even elevation 01'descent. 'In certain cases it'is practical to use a. wide workingplatform in order to cover 'a greater portion-o1 abuildingface or thelike, in which'instanceswings areattached to either side ol' tliecagetoextend the platform. Eachsuch 6 Claims. (01. 304-18) a wing has achainguicle from which thesuspending chain passesfto the above describedpair-fin the same manner as before. To facilitate the horizontalmovement of the cage below a bridge like structure, a wheeledcarriage-is used andlis so arrangedas tof roll uponv opposite sides ofthe web of I-beam or the like. Means is alsopro: vided for transferringthe cage from oneside to the other side of an obstruction that mightinterferey with the clear track of the supporting I-beam; On thefacesftof buildings or tank, lookouts are used tosupport the cage muchin the manner that painters scaffolds are hung in position. .7

' The novel features thatI consider characteristic of the v, inventionare set forthwith particularity in the appended claims. The invention,itself however, both as toits organization and its method .of operation,together with additional objects and advantages thereof, will bestbeunderstood from the following description of sp cific embodimentswhen, read in connection withthe accompanying drawings, in which 7Figure lis a view .in elevation of my scaffold inposition as suspendedfrom an overhead I- beami j v r Figure 2 is a" view taken on the planeof line 2-2 of Figure l;

i Figure 3 is an elevational view of my scaffold cage with lateralworking wings attached there- Figure 415 a sectional view taken'alongline 44 of Figure 3; and 1 Figure 5 is an enlargedfragmentary view of aportion of the elevator cage. I

A power-driven scaffold cage to overcome the prior art and'be fullyuseful must have at least two distinct characteristics; it must becapable of simpleandefiicient operation; and it must also be safe at alltimes irrespective of its vertical positioning. Accordingly, thepreferred embodiment ,of the invention comprises the elevator cage H)which is formed of tubing assembled in the'form of frame-work ofrectangular shape. At a mid-point vertically of the cage is the platform12 upon which an operator will stand in using the device. Incorporatedin the framework is chain guide means from above to below the platform,her being the pair of formed tubular members- 1'4, 15 which extend tothe spaceunder the platform. "On the bottom side of the platform betweenthe lower ends of tubes I4, I5 is "the cross-shaft 16 mounted forrotation in beafi'ngs wand having fixed chain pulleys 2o,

2i of the type designed to intimately receive and engage chain links.

Below each of the pulleys 20 and 2| are second chain pulleys 22 and 23respectively, which are also adjacent the lower end of the guide tubes[4, [5. It will be seen that each guide and one of each pair of upperand lower pulleys form a single assembly.

Chain 24 is led through guide tube I4 to pass below and around pulley 22thence upward to pass over and around pulley 20 from which it thendepends below the cage as shown. Similarly chain 25 passes through tube1 5, around lower pulley 23, upper pulley 2! from which it likewisedepends. In practice the two depending ends of the chain are joined intoa continuous element to form a loop below the cage which will haveweight to keep the chain in track with the upper pulleys.

Power is applied to the shaft l6 and pulleys 20, 2| by means of-motor30, sheave 3!, drive belt 32, sheave 33, worm shaft 34, worm 35, andworm gear 36 which is keyed to shaft IS. The motor 30 is of thewell-known reversible type and electric current is supplied thereto bycable 31 which is normally wired into circuit with th controller switch38 accessible to an operator standing on the cage platform.

It will be seen that when the shaft 16 is caused to rotate the chainpulleys will pass chain thereover in either direction and that therebythe cage will be caused to climb or descend the chains. By having thechains spaced apart in pairs as shown in Figure 1 a certain stabilityagainst tipping of the platform is provided and with the chains lyingclose to the face of a building, the cage may not tip away therefrombecause it will rest on such a face. Wheels 39 in such case roll on thebuilding or structure face and reduce friction as the device movesupward or downward. When it is desired to broaden the working platform,wings 40 and 42 are attached to the sides of the cage ill in cantileverfashion by means of pins 44 passing through ears 45 on the cage and ears46 on the wings. The wing 40 has a guide tube 48, and wing 42 has tube49 through which the chains 24 and 25 respectively have been led afterfirst having been removed from tubes l4 and I5. Idler pulleys 50, areassociated with tubes 48, 49 respectively and the chains each pass overone of these and thence to the lowermost pulleys mounted under theplatform, By thus moving the chains outward the base is broadened andtilting is precluded even though theworkman may stand atone outer end ofthe planking 43 used in the wings.

In supporting the cage from a building or tank structure theconventional look-outs are employed whereas when'it is desired tosuspend the device from a bridge-like structure in which there is anI-beam, as 60 in Figures 1 and 2, I use a carriage having wheels 63mounted on cheek plates 64 and 65, the latter of which is hinged at B6to swing to the dotted line position of Figure 2 when the hasp 61 israised from looking position with respect to dog 68. The carriage isthus openable when it is to be engaged on or removed from the lowerflanges of an I-beam.

In one of the cheek plates of the carriage is mounted the sheave overwhich passes rope H one end of which hangs free and the other end ofwhich is coupled to member 12 having the enlarged head 13 and from whichdepends the eye 14 into which is engaged the hook 1-5 to which arecoupled thechains 2.4 and 25. When the 6 6? is being rigged to a beam orto a look-out the chain will be hooked to eye 14 when the head 13 is outof engagement with the spring-pressed jaws 11. By pulling on rope H themember 12 is raised drawing with it the chains until the head passesabove the jaws 11 where it will be locked in place. Then by operatingthe motor to rotate the pulleys 22 and 23 the cage will climb the chainsthus suspended.

Occasionally it is necessary to transfer the device from one side of anobstruction beam 6| standing out from a side of beam 60 to the otherside. In that case I use the clamp bracket 80 which has an anchor cable8| which is engaged over hook 82 of the cage In. The cage is then letdown until the weight is taken on line 8! and the cage hook isdisengaged from eye 14 by means of rope 84 and its hook 85 whereupon thehook 15 is transferred to pin 85 temporarily, The

carriage 62 is then opened as has been described and transferred by theoperator past the obstruction and re-engaged on the I-beam. Again thecage is hooked to the carriage and the cage is ready for further use.

While I have shown and described particular embodiments of my invention,it will occur to those skilled in the art that various changes andmodifications may be made without departing from the invention and I,therefore, aim in the appended claims to cover all such modificationsand changes as fall within the true spirit and scope of the invention.

Having thus described my invention, I claim:

1. In a scaffold of the suspendedly supported power-driven type, anelevator cage having a platform; a chain guide above said platform; apair of chain pulleys one above the other both mounted below saidplatform; a suspended chain passing from said guide to below and aroundthe lower pulley of said pair thence over and around the upper pulleyfrom whence the free end depends therebelow; a second similar chainguide spaced horizontally from the first named chain guide on theopposite side of the center of said platform, and a pair of pulleys andchain roved therearound and over and disposed in like relation to saidplatform; and means for simultaneously rotating a like pulley of eachpair whereby the elevator cage climbs or descends said chain.

2. A scaffold of the suspendedly supported power-driven type,comprising: an elevator cage having a platform, wing platforms extendingoutward from either side of said cage, a chain guide on each said wingabove said platform, a first pair of chain pulleys one above the otherand both mounted below said platform, a second similar pair of chainpulleys mounted below said platform adjacent said first pair, asuspended chain passing from one said guide to below the lower pulley ofthe. first said pair thence around the same and over and around theupper pulley of the same pair from whence the free end dependstherebelow, a second suspended chain passing from the other said guideto the lower pulley of the second pair thence therearound and over andaround the upper pulley of the same pair from whence the free enddepends therebelow, and means for rotating one of the pulleys of eachsaid pair whereby the elevator climbs or descends said chain.

3. A scaffold of the suspendedly supported power driven type comprising.an elevator cage having a platform, a pair of spaced apart tubular chainguides extending from above the cage to below the platform, a pair ofchain pulleys mounted one above the other on said cage beneath theplatform adjacent to the lower end of each chain guide, a suspendedchain passing through each guide to below and around the lower chainpulley of the adjacent pair thence over and around the upper chainpulley of said pair from whence the free end of the chain dependstherebelow, and means to rotate the upper pulleys in unison whereby theelevator cage lower chain pulley of the adjacent pair thence over andaround the upper-chain pulley of said pair from whence the free end ofthe chain de-' pends therebelow, wing platforms extending outward fromeither side of said cage, a chain guide on each wing above said platformwhereby the having a platform, and a framework around the platform, apair of tubular guides for flexible suspension members such as chains,extendin from above the cage to below the platform adjacent to the endsof the cage, pulleys adjacent to the lower ends of said guides and belowthe platform for directing the suspension members laterally beneath theplatform, said cage having a power drive unit mounted thereonintermediate its'ends and spaced from said pulleys, the platformextending over said power drive unit and the framework extending beneaththe power drive unit, the power drive unit having a single shaftcarrying pulleys for receiving both of the suspension members.

6. A scaffold of the suspendedly supported power driven typecomprising-an elevator cage having a platform, wing platforms extendingoutwardly from either side of said first platform, frame memberscarrying the three platforms and projecting thereabove, providing theside walls of said cage, the intermediate frame members carrying thefirst named platform extending below the platform and providing asupportbe- 'neath the platform for power driven means to wings may likewise beguided by suspendedchains, and means to rotate the upper pulleys inunison whereby the elevator cage climbs or descends said chains and isheld substantially level thereby. I

5. A scaffold of the suspendedly supported power driven type comprisingan elevator cageoperate the scaffold, tubular chain guides mountedadjacent to the outer ends of said wing platforms and extending from thelevel of the top of the frame members downwardly below the platforms andpulleys beneath the platforms for directing suspension members such aschains from the guides to the power driven means.

ROYAL NEWTON RIBLET.

